Singapore prime minister Lee Hsien Loong will arrive in Tokyo later today to begin an official visit to Japan.

The four-day visit is to reaffirm links and advance cooperation with the world's third-largest economy.

It is also an opportunity for Lee to renew ties with his host, Japanese prime minister Shinzo Abe, who became his country's leader for the second time last December. They had met as prime ministers in 2007, when Abe first became prime minister for a year.

Lee will also deliver a keynote address at the annual Nikkei Conference on the Future of Asia.

Since taking charge, the Abe administration has appeared keen to prioritise ties with South-east Asia. Abe, his deputy Taro Aso and Foreign Minister Fumio Kishida each chose South-east Asia for their first official visit abroad.

Lee's visit comes amid China's rise, which has caused unease among some Asian nations. China is also embroiled in territorial disputes with both Japan and several South-east Asian countries.

Some observers believe South-east Asia would benefit geopolitically from a Japan that is more willing to counterbalance China in the region.

Japan is also showing early signs of an economic revival, after a series of policies rolled out by Abe, termed "Abenomics".

Lee is expected to exchange views with Abe on the latest developments in Japan and the region and to encourage Japan to keep playing an active role in South-east Asia.

Singapore-Japan relations are excellent and economic ties have been extensive since a free trade pact was signed in 2002. Trade totalled S$52.1 billion (US$41 billion) last year.

During his visit, Lee will meet Abe, Aso and other ruling party and opposition politicians, as well as businessmen.

On Thursday, he will speak at the Nikkei Conference, organised by media giant Nikkei and Japan Centre for Economic Research. He last spoke there in 2005.

Lee, who will be accompanied by MPs Zaqy Mohamad and Vikram Nair, returns home on Saturday.

During his absence, Deputy Prime Minister Teo Chee Hean will also be away on a working visit to France, from May 21 to 24.

Hence, the Acting Prime Minister will be: Deputy Prime Minister Tharman Shanmugaratnam from May 21 to 22, and Trade and Industry Minister Lim Hng Kiang from May 23 to 24.